Scattered thunderstorms from northern Indiana and lower Michigan are expected to move into Southern Ontario during the middle and late afternoon, the national weather service says.

A weather watch is an alert to the potential development of thunderstorms with large hail and damaging winds.

A heavy rainfall warning is posted for Sauble Beach, Bruce Peninsula and Tobermory. Between 40 and 60 millimetres of rain is expected, as a large low pressure system moves northward from Texas and into southern Ontario.

Temperatures are expected to climb to 23 C in the Kitchener area on Thursday, Environment Canada says. Southwest winds of 40 km-h may gust to 60 km-h.

Overnight, winds are expected to continue as the low falls to 14 C.

Friday, showers are expected as temperatures fall to 6 C by afternoon. By Saturday, a 1 C high with a 60 per cent chance of snow flurries.